Hypercholesterolemia is known to be one of the prime risk factors for ischemic cardiovascular disease, such as arteriosclerosis. Bile acid sequestrants have been used to treat this condition; they seem to be moderately effective but they must be consumed in large quantities, i.e., several grams at a time, and they are not very palatable.
MEVACOR.RTM. (lovastatin), now commercially available is one of a group of very active antihypercholesterolemic agents that function by limiting cholesterol biosynthesis by inhibiting the enzyme, HMG-CoA reductase. Another approach to limiting cholesterol biosynthesis is through inhibition of the enzyme HMG-CoA synthase.
U.S. Pat. No. 4,806,564 discloses certain .beta.-lactones of formula (i) ##STR2## which are useful as antihypercholesterolemic agents and are believed to function by inhibiting HMG-CoA synthase. Additional .beta.-lactones which have antihypercholesterolemic activity are disclosed in U.S. Pat. Nos. 4,816,477 and 4,847,271.